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United States Patent | 5,680,104 |
Slemon ,   et al. | October 21, 1997 |
An optical fiber security system includes an optical emitter connected to one end of an optical fiber and a detector connected to the other end. A random signal generator triggers the emitter to output a light pulse signal through the fiber. This generator also simultaneously triggers the detector to receive the light pulse signal. A comparator compares the light pulse signal that is received by the detector with an optimum reference to adjust and conform the emitter output with the reference. Also, a monitor determines whether a particular identifiable characteristic of the light pulse signal is within a predetermined range of values. Whenever there is not a simultaneous emission and detection of the light pulse signal, or whenever the light pulse characteristic is outside the predetermined range of values, the system alarms.
Inventors: | Slemon; Charles S. (Encinitas, CA); Lafferty; William Michael (Leucadia, CA); Diamond; Anthony E. (San Diego, CA) |
Assignee: | Volution (San Diego, CA) |
Appl. No.: | 652913 |
Filed: | May 31, 1996 |
Current U.S. Class: | 340/568.2; 340/600 |
Intern'l Class: | G08B 013/14 |
Field of Search: | 340/568,571,600,540,541,565,566,555,556,427,432,573 359/187,179 |
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